Another Alphabay/silkroad/silkbay/alpharoad whatever it will be called, will pop up soon enough. I'm a huge long term Zcash bull and accumulating more and more slowly. Just give it a year or two or three. Same with XMR, it may take a while, but when it goes, it goes big time.
I doubt any of markets will add Zcash, Monero or ETH again. Precident exist.
Afer Alphabay added this coins the servers was busted. Coincident?
I do not think so.
This will keep any markets away from this coins. They hardly will get real usage soon. I do not see why they should rise again in long.
A lot of people was investing in Zcash and Monero just because of Alphabay and real usage.
ETH have ICOs and dapps online it will probably suffer less from Alphabay closure. But have another problem - like Scalabilityand questionable PoS. Many people think that PoS is a bad idea.
Bitcoin in my opinion after Segwit activation is likely to be Your Majesty again. Especialy with new coming futures like confidential transaction, lighting network, mast,rsk smart.